Grader



June 19, 1928.

T. H. HARDEN GRADER R: a m, m d HY I B n 1 M. O m x ATTORNEYS WITNESSESPatented June 19, 1928.

UNITED STATES THOMAS HUDSON HARDEN, QF DAWSON, GEORGIA.

GRADER.

Application filed August 27, 1926.

My invention relates generally to improvements in road or street gradersof that type which includes a mold board and a cutting or scrapingblade-bit detachably secured to the mold board, and it consists in thecombinations, constructions and arrangements herein described andclaimed.

An object of the present invention is the provision in a grader of thecharacter described of a blade-bit which can he used a relatively longtime in service without resharpening or replacement.

A further object of the invention is the provision in a grader of thecharacter described of a reversible double-edged bladebit and efficientmeans for clamping the blade-bit securely to an associated mold boardwhen either of the cutting edges of the blade-bit is in position foruse.

Other objects and advantages of the invention will be apparent from thefollowing description, considered in conjunction with the accompanyingdrawings, in which:

Figure 1 is a fragmentary side elevation of a grader having a mold boardequipped with a blade-bit embodying the invention.

Figure 2 is a fragmentary vertical section through the associatedportions of the mold board and the blade-bit.

In Figure 1, the numeral 1 designates a mold board which is supported,adjustably or otherwise, in any suitable known manner from the framestructure 2 of a road or street grader. The specific means forsupporting the mold board forms no part of the present invention andtherefore will not be described.

The mold board 1 has the lower edge portion offset rearwardly at 2 andis substantially conveXo-concave in vertical sectional configurationwith the concavely curved face at the front, as is usual in a grader ofthe type hereinbefore referred to. A blade-bit formed according to theinvention is indicated at 4: and is made of a suitable material,preferably steel. This blade-bit is fashioned so that its rear face willbe convexly curved from the lower edge of the blade bit to the upperedge of the blade-bit substantially in conformity with the generalcurvature of the front face of the mold board. The front face 6 of theblade-bit is nearly plane but may be slightly concave from the loweredge of the blade-bit to its upper edge as shown. The lower and upperedge portions of the blade-bit taper toward their edges to pro- SerialNo. 131,956.

vide cutting edges 7 and 8 respectively at the lower and upper edges ofthe blade-bit. The width of the improved blade-bit from its upper edgeto its lower edge is considerably greater than is usual for a blade-bitfor a grader of the type referred to.

The blade-hit is provided with a series of spaced transverse openings 9intermediate its upper and lower edges andcorresponding in number andrelative arrangement with transverse openings 10 through the offsetlower edge portion 2 of the mold board. The openings 9 preferably aresquare in cross section for part of their length from the rear face ofthe bitblade but are enlarged at their forward ends to produce thetapering counter-bores at 9 for the reception of the heads of bolts 11which areprojected through registering openings 9-1() and have theirshanks engaged with nuts 12 which are tightened against the rear face ofthe offset lower edgeportion 2 of the mold board to secure the blade-bitto the mold board. The heads of the bolts 11 thus will be flush with thefront faces of the blade bit when the nuts 12 have been tightened. Theportions of the shanks of the bolts 11 which extend through thenon-circular open-- ings '9 also are non-circular to prevent turning ofthe bolts when the nuts are tightened.

The convexly curved rear face of the blade-bit will contact for a partof its area with the concavely curved front face of the mold board. Inorder to relieve the bolts 11 of some of the strain incident to themaintaining of the blade-bit rigid with the mold board and to assure arelatively firm engagement of the blade-bit with the mold board, Iprovide a spacing rod or bar 13, which is disposed between the convexlycurved rear face of the blade-bit and the front face of the offset loweredge portion 2 of the mold board below the level of the series of bolts11 and it is manifest that this spacing rod 13 will be clamped securelyin place betwen the blade-bit and the lower edge portion of the moldboard when the nuts 12 have been tightened on the bolts 11. The member13 is substantially rectangular in cross sectional configuration butdecreases slightly in thickness toward its upper edge.

The openings 10 in the lower edge portion of the mold board are locatedat a distance above 'the edge of the mold board sufficient to assure thesupporting of the blade-bit on the mold board with the lower edgeportion of the blade-bit depending below the lower edge of the moldboard when the blade-bit has been secured to the mold board in themanner hereinbetore described with either of its edges 7 or 8 turneddownward. The front face of the blade-bit will be substantiallycontinuous with the trout face of the portion of the mold board abovethe blade-bit so that the loose earth or other material which impingesagainst the Front faces of the mold board and the blade-bit will notlodge between the upper edge of the blade-bit and the mold board andmoreover the upper edge of the blade hit will be protected against wearby reason ot its position on the concavelv curved front face of themold-board.

From the foregoing description of the various parts of the device, theoperation thereof may be readily understood. The blade-bit, beingdouble-edged and reversible. will be capable of use in service tor atleast twice the time that a single-edged blade could be used withoutbeing re-sharpened. Moreover, the double-edged blade-bit can have bothits cutting edges sharpened a t. the same time, thus also making foreconomy in the time and labor that will be required to keep aroad-grader that is equipped with th% invention in condition torservice.

\Vhile the spacing member 13 is shown as being substantiall rectangularin cross section, it is obvious that it. may have any other desirablecoutiguraticai in cross section without departing from the spirit andscope ot the invention.

()bviousdy. the invention is susceptible of embodiment in terms otherthan that which is illustrated in th accompz'inving drawings and Itherefore, consider as my own all srch modifications and adaptationsthereof as fairly fall within the scope of the appended claims.

I claim:-

1. In combination a, transversely curved mold board having a rearwardlvotlset lower longitudinal edge. a concavo convex scraper blade arrangedwith its convex snrl'ace against the concave surface of the mold boardwith its upper edge merging into and continuous with said concavesurface. spacer elements interposed between the onset edge and scraperblade. and t'astcnings passing transversely through the scraper bladeand oti'set end.

2. In a grader. the combination with a mold board having its front faceadjacent to its lower edge substantially concave in vertical sectionalconfiguration. a blade-bit having its longitudinal edges tormed ascutting edges and having its rear face curved convexly transversely ofthe blade-bit to conform substantially to the vertical curvature of thefront face of the mold board, said blade-bit and the lower edge portionol. said mold board having alincd transverse openings, bolts passingthrough said open ings and nuts threadcdlv engaged with said bolts forcooperating with said bolts to clamp said blade-bit to said mold boardso that the lower edge portion o 1' said blade-bit; will depend belowthe lower edge ol' the mold board. and an elongated spacin l' memberdisposed between said hla le-bit and said mold board below the level ofsaid bolts.

ll. 1n :1 grader. a mold board having a. i'earwardlv otlset lower edgeportion and having its front face concavclv curved in vertical sectionalconfiguration above the juncture of said oti'set portion with theremaindcr oi the mold board. a blade-bit having both its longitudinaledgesformed to produce cutting edges and having its rear face. curvedconvcxlv transversely ol the blade-bit to conform to the concavelvcurved portion of the trout face of the mold board, the front face ofthe blade-bit being. slightly convex in transverse curvature fasteningdevices securing said blade-bit along its lougitiulinal median line tothe otiset portion ot said mold board, the lower edge portion of saidblade-bit. depending below the lower edge of said mold board, and anelongated non-circular spacing member disposed between said blade-bitand the otl'set portion of said mold board below the level of saidfastening devices.

'IHOTKIAS l'lUDSON IIARDEN.

(ill

